obama visiting this predominantly hispanic las vegas high school to build support for immigration reform. >> now is the time to find a better way to welcome the striving, hopeful immigrants who still see america as the land of opportunity. >> reporter: the president's plan calls for bolstering border security you cracking down on employers hiring undocumented workers and perhaps most controversially, allowing the estimated 11 million undocumented immigrants living in the u.s. to earn citizenship by paying taxes and passing a background check, among other requirements. >> this is not just a debate about policy. it's about people. >> reporter: mr. obama described a largely similar bipartisan plan in the senate as encouraging, but republicans are already warning the president that there are limits to their willingness to compromise. >> if this endeavor becomes a bidding war to see who can come up with the sizest, quickest and cheapest pathway to green card possible, this thing is not going to go well, folks. >> reporter: still, after winning more than 70% of the latino votes last november,